The present invention relates to a method and article of manufacture and apparatus for sizing and orienting a battery grid structure and finds adaptation in the battery grid industry and, in particular, relates to the formation of individual grid bodies to render them of a consistent and uniform dimension.
The subject invention specifically is addressed to methods and an apparatus for sizing and orienting grid structures having open networks thereon whereby the structures are oriented and dimensioned to a predetermined size. Such grid structures are generally made by expanding a metal sheet to form an open network structure and thereafter applying paste thereto by means readily available in the art.
The step of expansion in the process to form the expanded structure may be readily made by conventional processes, such as disclosed in U.S. Pat. No. 3,891,459. After expansion, the expanded structure is subjected to a sizing and orienting process wherein the structure is formed to a predetermined size. This process and apparatus for carrying out the same will be described in more detail hereinafter. After this step the expanded structure is pasted and the pasting is accomplished by moving the structure into a zone where an active material, generally a thick, lead-containing paste, is applied to the open network. Various means may be used to apply the active material to the expanded structure. In order to deliver a uniform charge for distribution upon and into the open network of the grid without materially deforming the same, pasting machines are utilized and are generally of the so-called Lund or fixed orifice type or the Winkel or belt type. In the Lund type, a strip of battery paste is fed between a pair of rollers rotating to apply pressure to the grid, the paste being thereby forced into the grid structure. In the Winkel belt type, the grids are fed horizontally on a belt under a roller where the battery paste is applied. Pasting machines have also been developed that use ultrasonic energy to convert battery pastes from their normally nonflowable form to a flowable form. After the expanded structure is subjected to the direct and continuous charge of paste, the pasted grid is moved into a wiping or leveling zone where a doctor blade or the nip of a set of spaced apart rollers produce a uniform paste distribution. In this fashion the paste is compressed by mechanical forces into the interstices of the network, the leveling being such as to merely allow the grid structure itself to freely pass through the zone and undergo only minimum, if any, deformation. Thereafter, the pasted grid is subjected to a drying operation to thereby affix the paste to the network. In a commercial operation, the production of grids is generally made from a large length of sheet material so that there are a multiplicity of grid structures thereon comprising expanded and unexpanded portions. After drying, the structures must be subjected to a separation or cutting operation to sectionalize and set free the individual grids for further processing. Since such structures are more or less in a delicate state, any slitting or cutting must be carefully done so as not to cause loss of paste from the pasted network. It will be appreciated that the battery grids are easily deformable and may lose their character if adequate means are not employed to handle them. Any undue treatment would cause disruption or loss of paste and, therefore, rejection of the grid structure.
In U.S. Pat. No. 1,982,485 to Salmon, et al., a battery grid is described having an expanded portion.
In U.S. Pat. No. 3,310,438 to Huffman, et al., a dispersion strengthened lead battery grid structure is disclosed. The structure is formed from expanded lead stock.
In U.S. Pat. No. 3,686,916 to Smith, et al., a special roll is described for use in the manufacture of battery plate grids.
In U.S. Pat. Nos. 3,881,952, to Wheadon, et al., and 3,891,459, to McCartney, Jr., et al., expanded grid structures are disclosed having nodes that have been flattened by rolling techniques to form certain polygonal configurations.
In U.S. Pat. No. 3,947,936 to Wheadon, expanded metal is disclosed that has been coined to enhance the characteristics thereof.
In U.S. Pat. No. 4,016,633, a method is disclosed for making a battery grid via casting that is subsequently flattened by a pressing process.
Briefly, in accordance with this invention, a battery grid formed from stock material is described and claimed, the grid having expanded and unexpanded portions thereon wherein the unexpanded portions lie centrally thereon and the expanded portions are of greater thickness than the unexpanded portions, said expanded portions being provided with nodes, said method comprising continuously advancing the stock material along a predetermined path, forming spaced apart cut out portions on said stock material and simultaneously working the expanded portions to orient and size the same whereby the faces of the nodes are displaced so that the planes of opposed faces thereof are unparallel to each other. The subject invention also relates to the article of manufacture produced by the method herein described, the article comprising a metal grid structure defining a header and a lug connecting portion thereon, an open network depending from the header over the entire length thereof, said open network being provided with nodes having elements projecting therefrom to define cells, said nodes having trapezoidal configurations when viewed in cross section.
The aforementioned features with the objects and advantages which become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, referenced being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout.